Systems are known that fabricate three-dimensional (3D) objects from digital models of such objects. One type of system, commonly used in rapid prototyping, involves an additive manufacturing process, in which a computer-controlled machine builds up a 3D object from a series of cross-sections by applying successive layers of liquid, powder or other material.
Systems are also known that render a digital 3D model on a two-dimensional (2D) display, such as a conventional 2D computer screen. One type of 3D rendering system divides the 3D model into cross-sectional layer images and then reassembles the layers on the screen to depict the modeled object in three dimensions. Computed tomography (CT) and magnetic resonance imaging (MRI) machines similarly render 3D images on a screen by reassembling 2D layer images. Part of the rendering process in such systems may involve computing a color and opacity value for each pixel in each 2D layer image.
Some artists have produced 3D effects by painting on each of a number of glass or acrylic sheets and then stacking them together. Such a multi-layer work of art thus comprises a stack of 2D sheets stacked along a third dimension, yielding a 3D structure. The work of art can depict a subject in 3D because painted portions corresponding to portions of the subject reside at corresponding depths within the structure over a range of viewing directions.
Attempts have been made to electronically produce displays that provide an effect similar to that of the 3D artistic works described above. One such system included multiple 2D electronic displays that combined images using beamsplitters. Others involved projecting light onto thin layers of fog, parallel sheets of water droplets, or shutter planes. In all of these cases, the density and number of projection barriers is limited by cost or other practical considerations such as projector placement and refresh rate. Thus, it would be desirable to provide an improved automated process for creating a realistic 3D effect.